MuscoviteMuscoviteMuscovite (also known as common mica, isinglass, or potash mica[5]) is
a hydrated phyllosilicate mineral of aluminium and potassium with
formula KAl2(AlSi3O10)(FOH)2, or (KF)2(Al2O3)3(SiO2)6(H2O). It has a
highly perfect basal cleavage yielding remarkably thin laminae
(sheets) which are often highly elastic. Sheets of muscovite 5 m × 3
m have been found in Nellore, India.[6]
MuscoviteMuscovite with beryl (var. morganite) from Paprok, Afghanistan
MuscoviteMuscovite (var. alurgite), from Prabornaz Mine, Aosta Valley, Italy
MuscoviteMuscovite has a
Mohs hardnessMohs hardness of 2–2.25 parallel to the [001] face,
4 perpendicular to the [001] and a specific gravity of 2.76–3. It
can be colorless or tinted through grays, browns, greens, yellows, or
(rarely) violet or red, and can be transparent or translucent. It is
anisotropic and has high birefringence
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RedRedRed is the color at the end of the visible spectrum of light, next to
orange and opposite violet. It has a dominant wavelength of
approximately 625–740 nanometres.[1] It is a primary color in the
RGB color modelRGB color model and the CMYK color model, and is the complementary
color of cyan. Reds range from the brilliant yellow-tinged scarlet and
vermillion to bluish-red crimson, and vary in shade from the pale red
pink to the dark red burgundy.[2] The red sky at sunset results from
Rayleigh scattering, while the red color of the
Grand CanyonGrand Canyon and other
geological features is caused by hematite or red ochre, both forms of
iron oxide
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Hydrate
In chemistry, a hydrate is a substance that contains water or its
constituent elements. The chemical state of the water varies widely
between different classes of hydrates, some of which were so labeled
before their chemical structure was understood.Contents1 Chemical nature1.1 Organic chemistry
1.2 Inorganic chemistry
1.3
ClathrateClathrate hydrates2 Stability
3 See also
4 ReferencesChemical nature[edit]
Organic chemistry[edit]
In organic chemistry, a hydrate is a compound formed by the addition
of water or its elements to another molecule. For example: ethanol,
CH3–CH2–OH, is the product of the hydration reaction of ethene,
CH2=CH2, formed by the addition of H to one C and OH to the other C,
and so can be considered as the hydrate of ethene. A molecule of water
may be eliminated, for example by the action of sulfuric acid
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FluorescenceFluorescenceFluorescence is the emission of light by a substance that has absorbed
light or other electromagnetic radiation. It is a form of
luminescence. In most cases, the emitted light has a longer
wavelength, and therefore lower energy, than the absorbed radiation.
The most striking example of fluorescence occurs when the absorbed
radiation is in the ultraviolet region of the spectrum, and thus
invisible to the human eye, while the emitted light is in the visible
region, which gives the fluorescent substance a distinct color that
can only be seen when exposed to UV light
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AluminiumAluminiumAluminium or aluminum is a chemical element with symbol Al and
atomic number 13. It is a silvery-white, soft, nonmagnetic and
ductile metal in the boron group. By mass, aluminium makes up about 8%
of the Earth's crust; it is the third most abundant element after
oxygen and silicon and the most abundant metal in the crust, though it
is less common in the mantle below. The chief ore of aluminium is
bauxite.
AluminiumAluminium metal is so chemically reactive that native
specimens are rare and limited to extreme reducing environments.
Instead, it is found combined in over 270 different minerals.[5]
AluminiumAluminium is remarkable for its low density and its ability to resist
corrosion through the phenomenon of passivation
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AluminumAluminiumAluminium or aluminum is a chemical element with symbol Al and
atomic number 13. It is a silvery-white, soft, nonmagnetic and
ductile metal in the boron group. By mass, aluminium makes up about 8%
of the Earth's crust; it is the third most abundant element after
oxygen and silicon and the most abundant metal in the crust, though it
is less common in the mantle below. The chief ore of aluminium is
bauxite.
AluminiumAluminium metal is so chemically reactive that native
specimens are rare and limited to extreme reducing environments.
Instead, it is found combined in over 270 different minerals.[5]
AluminiumAluminium is remarkable for its low density and its ability to resist
corrosion through the phenomenon of passivation
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OxygenOxygenOxygen is a chemical element with symbol O and atomic number 8.
It is a member of the chalcogen group on the periodic table, a highly
reactive nonmetal, and an oxidizing agent that readily forms oxides
with most elements as well as with other compounds. By mass, oxygen is
the third-most abundant element in the universe, after hydrogen and
helium. At standard temperature and pressure, two atoms of the element
bind to form dioxygen, a colorless and odorless diatomic gas with the
formula O
2. Diatomic oxygen gas constitutes 20.8% of the Earth's atmosphere
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FluorineFluorineFluorine is a chemical element with symbol F and atomic number 9. It
is the lightest halogen and exists as a highly toxic pale yellow
diatomic gas at standard conditions. As the most electronegative
element, it is extremely reactive: almost all other elements,
including some noble gases, form compounds with fluorine.
Among the elements, fluorine ranks 24th in universal abundance and
13th in terrestrial abundance. Fluorite, the primary mineral source of
fluorine which gave the element its name, was first described in 1529;
as it was added to metal ores to lower their melting points for
smelting, the Latin verb fluo meaning "flow" gave the mineral its
name. Proposed as an element in 1810, fluorine proved difficult and
dangerous to separate from its compounds, and several early
experimenters died or sustained injuries from their attempts
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HydrogenHydrogenHydrogen is a chemical element with symbol H and atomic number 1.
With a standard atomic weight of 7000100800000000000♠1.008, hydrogen
is the lightest element on the periodic table. Its monatomic form (H)
is the most abundant chemical substance in the Universe, constituting
roughly 75% of all baryonic mass.[7][note 1] Non-remnant stars are
mainly composed of hydrogen in the plasma state. The most common
isotope of hydrogen, termed protium (name rarely used, symbol 1H), has
one proton and no neutrons.
The universal emergence of atomic hydrogen first occurred during the
recombination epoch. At standard temperature and pressure, hydrogen is
a colorless, odorless, tasteless, non-toxic, nonmetallic, highly
combustible diatomic gas with the molecular formula H2. Since hydrogen
readily forms covalent compounds with most nonmetallic elements, most
of the hydrogen on Earth exists in molecular forms such as water or
organic compounds
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Potassium Fluoride
Potassium fluoride is the chemical compound with the formula KF. After
hydrogen fluoride, KF is the primary source of the fluoride ion for
applications in manufacturing and in chemistry. It is an alkali halide
and occurs naturally as the rare mineral carobbiite. Solutions of KF
will etch glass due to the formation of soluble fluorosilicates,
although HF is more effective.Contents1 Preparation
2 Applications in organic chemistry
3 Safety considerations
4 ReferencesPreparation[edit]
Potassium fluoride is prepared by dissolving potassium carbonate in
excess hydrofluoric acid. Evaporation of the solution forms crystals
of potassium bifluoride. The bifluoride on heating yields potassium
fluoride:K2CO3 + 4HF → 2KHF2 + CO2↑ + H2O
KHF2 → KF + HF↑The salt must not be prepared in glass or porcelain vessels as HF and
the aqueous solution of KF corrode glass and porcelain
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Aluminate
In chemistry aluminate is a compound containing an oxyanion of
aluminium, such as sodium aluminate. In the naming of inorganic
compounds it is a suffix that indicates a polyatomic anion with a
central aluminum atom.[1]Contents1
Aluminate oxyanions
2 Mixed oxides containing aluminium
3 Hydroxoaluminates
4
Aluminate glasses
5 Applications of aluminates
6
Aluminate suffix used in the naming of inorganic compounds
7 Aluminates made using new raw materials
8 Notes
Aluminate oxyanions[edit]
AluminiumAluminium oxide (alumina) is amphoteric: it dissolves in both bases
and acids. When dissolved in bases it forms hydroxyaluminate ions in
the same way as aluminium hydroxide or aluminium salts. The
hydroxyaluminate or hydrated aluminate can be precipitated and then
calcined to produce anhydrous aluminates
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Silicate
A silicate is a compound containing an anionic silicon compound. The
great majority of the silicates are oxides, but hexafluorosilicate
([SiF6]2−) and other anions are also included.
"Orthosilicate" is the anion SiO4−
4 or its compounds. Related to orthosilicate are families of anions
(and their compounds) with the formula [SiO2+n]2n−. Important
members are the cyclic and single chain silicates [SiO3]2− n and
the sheet-forming silicates [SiO2.5]− n.[1]
Silicates constitute the majority of Earth's crust, as well as the
other terrestrial planets, rocky moons, and asteroids. Sand, Portland
cement, and thousands of minerals are examples of silicates. Silicate
compounds, including the minerals, consist of silicate anions whose
charge is balanced by various cations. Myriad silicate anions can
exist, and each can form compounds with many different cations. Hence
this class of compounds is very large
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Basal Cleavage
Cleavage, in mineralogy, is the tendency of crystalline materials to
split along definite crystallographic structural planes. These planes
of relative weakness are a result of the regular locations of atoms
and ions in the crystal, which create smooth repeating surfaces that
are visible both in the microscope and to the naked eye.[1]Contents1 Types of cleavage
2 Parting
3 Uses
4 See also
5 ReferencesTypes of cleavage[edit]Miller indices h k ℓ Cleavage forms parallel to crystallographic planes:[1]Basal or pinacoidal cleavage occurs when there is only one cleavage
plane. Graphite has basal cleavage. Mica (like muscovite or biotite)
also has basal cleavage; this is why mica can be peeled into thin
sheets.
Cubic cleavage occurs on when there are three cleavage planes
intersecting at 90 degrees
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Doce River
The
Doce RiverDoce River (literally the "sweet river"; Portuguese: Rio Doce
[ˈʁiu ˈdos(i)]) is a river in southeast
BrazilBrazil with a length of 853
kilometres (530 mi). The river basin is economically important.
In 2015 the collapse of a dam released highly contaminated water from
mining into the river causing an ecological disaster.Contents1 Course
2 Economic value
3 Climate
4 Ecological disaster
5 References
6 External linksCourse[edit]
The
Doce RiverDoce River is formed by the junction of the Piranga and the
Carmo[1] near the historical city of Ouro Preto, whose sources are
located in the foothills of the Mantiqueira and Espinhaço mountain
chains at altitudes of about 1,200 m
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Elasticity (physics)
In physics, elasticity (from Greek ἐλαστός "ductible") is the
ability of a body to resist a distorting influence and to return to
its original size and shape when that influence or force is removed.
Solid objects will deform when adequate forces are applied on them. If
the material is elastic, the object will return to its initial shape
and size when these forces are removed.
The physical reasons for elastic behavior can be quite different for
different materials. In metals, the atomic lattice changes size and
shape when forces are applied (energy is added to the system). When
forces are removed, the lattice goes back to the original lower energy
state. For rubbers and other polymers, elasticity is caused by the
stretching of polymer chains when forces are applied.
Perfect elasticity is an approximation of the real world. The most
elastic body in modern science found is quartz fibre[citation needed]
which is not even a perfect elastic body
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